System Integration Engineer

We are looking for a System Integration Expert (Core Telco) as a contractor (freelancer) for a long-term project (1 year+) with a hybrid work arrangement.

Project and profile details:

Domain: Telco

Location: Budapest, Hungary ( No remote applications accepted outside of Hungary)

Start: October, 2026

End: December, 2027

Work engagement: Contractor-type, full-time and hybrid ( 2 times per week office work)

If you are interested, please send your CV and your hourly rate expectation to our email at [email protected] or via DM.

System Integration Expert (Telco)

Senior, hands-on system integration engineer responsible for end-to-end integration of BSS/OSS and Core Network systems.

Key responsibilities:

Own API and interface integration between internal systems and external vendors.

Analyze interface specifications (REST/OpenAPI, SOAP, HTTP2, Kafka, MQ, file-based integrations).

Troubleshoot end-to-end integration issues across multiple systems.

Coordinate technical discussions with vendors and internal engineering teams.

Drive issue resolution when interfaces, APIs or data models do not align.

Support SIT/UAT, log analysis, packet trace analysis and production readiness.

Required experience:

5+ years in system integration.

Strong understanding of API-based integrations and distributed systems.

Experience with BSS/OSS and/or Core Network integration projects.

Able to read logs, traces and API traffic, identify root causes, and drive vendors to resolution.

Excellent communication skills and ability to lead technical workshops.

Profile:

A pragmatic, hands-on engineer who takes ownership, quickly identifies integration gaps, and gets multiple vendors to converge on a working end-to-end solution. Not a project manager—an engineer who can dive into the technical details and unblock delivery.